JPH0795241B2 - Reactor safety protection device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a reactor safety protection device for operating a controlled device when two independent operating means are activated.

[Conventional technology]

In a nuclear power plant, in order to ensure the safety of a nuclear reactor, a safety protection device is provided in order to prevent an abnormal transient state or the like when it may occur.
For example, in Japanese Patent Laid-Open No. 61-118801, a quadrupled sensor and a channel set signal processor (signal processing means) are connected in series, and each output signal of four channel set signal processors is input. 1 shows a reactor safety protection device with two logic circuits. Each logic circuit constitutes a 2-out-of-4 logic circuit.
The logic circuit 1 outputs a protection device activation signal. This protector energization signal causes the breakers that power the control rod controller coils to open and scram the reactor. Further, the protective device energizing signal output from the logic circuit 2 prompts the operation of the emergency boric acid injector and the spray in the storage container.

In addition, Nuclear Handbook, 1976, p263-267, especially
Two out-of-four logic circuits are shown in Table 9.6 of p264.

[Problems to be solved by the invention]

In Japanese Patent Laid-Open No. 61-118801, the logic circuit is 2 out of 4.
Although it is shown to be configured by logic, a specific circuit configuration of 2 out of 4 is not shown. On the other hand, Tables 9 and 6 of the Nuclear Handbook show the concrete circuit configuration of 2 out of 4.

Japanese Patent Laid-Open No. 61-118801 shows a reactor safety protection device for a pressurized water reactor. This reactor safety protection device
One 2 out of 4 logic circuit operates one coil of the control rod controller. However, the solenoid valve for the scrum that operates the control rod drive control unit, which is the target of the conventional reactor safety protection system for boiling water reactors, has 2
It has two exciting coils. Therefore, JP-A-61-118
Based on the description of Japanese Patent No. 801, it is necessary to provide one 2 out of 4 logic circuit for each exciting coil.
Moreover, it is conceivable that these 2 out of 4 logic circuits are applied to the 2 out of 4 logic circuits composed of eight switches shown in Tables 9 and 6 of the above-mentioned Nuclear Power Handbook, p264.

In this way, when two independent operating means are provided as the operating means of one controlled device (for example, when two independent exciting coils are provided as in a boiling water reactor), Providing two out-of-four logic circuits for each operating means to operate each operating means requires 16 switches. The reliability of the switch decreases exponentially with the passage of time, and if the failure rate of the switch is the same, the rate of decrease in reliability increases as the number of switches increases. After all, there is a limit to the improvement of the reliability of the reactor safety protection device as the number of switches forming the two out-of-four logic circuit increases, and there is a strong demand for the development of a reactor safety protection device having higher reliability.

An object of the present invention is to provide a reactor safety protection device capable of reducing the number of switches of 2 out of 4 logic circuits and improving the reliability of reactor protection.

[Means for solving problems]

A feature of the present invention is that a quadruple signal processing system is provided, each having signal processing means for outputting a trip signal based on an output signal of a sensor that is quadrupled and installed, and is always energized. 8 switches and 2 operating means constitute a 2 out of 4 logic device,
The eight switches are opened and closed by a quadruple signal processing system.

[Action]

According to the present invention, the number of switches forming the 2 out of 4 logic circuit is reduced, so that the reliability is remarkably increased and the reliability of reactor protection can be improved.

〔Example〕

A specific embodiment of the control protection device according to the present invention will be described below with reference to FIGS. 1 and 2.

The reactor safety protection device according to the present embodiment has four systems of signal processing including one signal processing device, one switching circuit and one diagnostic device (for example, the signal processing device 1, the switching circuit 19A and the abnormality diagnostic device 22A). It has lines 25A to 25D. In each signal processing system, the signal processing devices 1 to 4 are connected to the sensors A ₁ to
A ₄ , ..., N _{1 to} N ₄ , the signal processing device 2 to the sensors A _{2 to} N ₂ ,
The signal processing device 3 is connected to the sensors A _{3 to} N ₃ and the signal processing device 3
Are connected to sensors A _{4 to} N ₄ . Here, four sensors (eg A ₁ , A ₂ , A ₃ ,
A ₄ ) are arranged close to each other and measure the same state quantity of the nuclear power plant (hereinafter referred to as the same kind of state quantity). The sensors with different alphabets measure different state quantities or state quantities at different places (hereinafter referred to as different kinds of state quantities) even if the state quantities are the same. The signal processing devices ₁ , ₂ , ₃ and ₄ take in the signals output from the redundant sensors A _{1 to} N ₁ , A _{2 to} N ₂ , A _{3 to} N ₃ and A _{4 to} N ₄ , respectively. The arithmetic processing is performed, and when the processing result exceeds a specified value, trip signals a to d for causing the plant to scramble are output.

The changeover circuit 19A has a changeover switch 20 and a power source 21 as shown in FIG. 2 as an example. The changeover switch 20 is
It has fixed contacts 20A and 20B, a fixed terminal 20C, and a movable contact 20D that is always connected to the fixed terminal 20C. The power supply 21 is connected to the fixed contact 20B. The switching circuits 19B to 19D also have the same structure as the switching circuit 19A. The fixed contacts 20A of the switching circuits 19A to 19D are connected to the output ends of the signal processing devices 1 to 4, respectively. In the state where each of the signal processing devices 1 to 4 is functioning normally, the movable contact of each of the switching circuits 19A to 19D
20D is connected to fixed contact 20A.

The power circuit (switchgear) 5 has two switchgear parts (first switchgear) 5A and switchgear parts (second switchgear) 5B arranged in parallel. Each of the switch parts 5A and 5B is composed of four relays (or contactors). The switch part 5A connects the relay 8 and the relay 9 in series, and connects the relays 10 and 11 arranged in parallel to the relay 9 in series. The relay 8 is connected to the power supply 6. The switch part 5B connects the relay 12 and the relay 13 in series, and connects the relays 14 and 15 arranged in parallel to the relay 13 in series. The power supply 7 is connected to the relay 12. Relay 8 ~
Reference numeral 15 has movable contacts 8A to 15A and fixed contacts 8B to 15B, respectively.

The relays 8 and 14 are signals for activating the relays and are connected to the fixed terminal 20C of the signal switching circuit 19A for inputting the trip signal a. Similarly, relays 9 and 15
The relays 10 and 12 are connected to the fixed terminal 20C of the signal switching circuit 19B in order to input the trip signal b which is an operation signal.
Is connected to the fixed terminal 20C of the signal switching circuit 19C for inputting the trip signal C of the operation signal, and the relay 11 and
Reference numeral 13 is connected to the fixed terminal 20C of the signal switching circuit 19D for inputting the trip signal d which is an operation signal. During normal operation of the nuclear power plant, the movable contacts 8A to 15A are closed, and the movable contacts 8A to 15A are in contact with the fixed contacts 8B to 15B, respectively.

The output ends of the relays 10 and 11 (the output end of the switch part 5A) are connected to the exciting coil 16 of the scrum electromagnet 18. relay
The output ends of 14 and 15 (the output end of the switch portion 5B) are connected to the exciting coil 17 of the scrum electromagnet 18. The scrum electromagnet 18 is provided in the solenoid valve 19 for scrum.

22A to 22D are abnormality diagnosis devices that diagnose the presence or absence of an abnormality in each of the signal processing devices 1 to 4.

In this embodiment, the relays 8 to 15 and the exciting coils 16 and 17 in the power circuit 5 constitute a 2-out-of-4 logic circuit. In other words, the switch unit 5A, the exciting coil 16 connected to the switch unit 5A, the switch unit 5B and the exciting coil 17
It can be said that it constitutes an out-of-four logic circuit.

Here, when the signal processing devices 1 to 4 output the trip signals a to d while the signal processing devices 1 to 4 are functioning normally (plant abnormal state), the movable contact 8A and 14A responds to trip signal a by moving contacts 9A and 1
5A is opened by the trip signal b, the movable contacts 10A and 12A are opened by the trip signal C, and the movable contacts 11A and 15A are opened by the trip signal d, so that the excitation coils 16 and 17 are in the non-excitation state. In this way, the excitation coils 16 and 17
When both of them are in the non-excited state, the scrum electromagnet 18 operates to open the scrum solenoid valve 19. This allows the control rod drive (not shown) to quickly insert the control rod into the core,
The reactor is scrummed.

The 2 out of 4 logic circuit of the present embodiment which operates as described above has a 2 out of 4 logic configuration in which "0" is prioritized.

In this embodiment, the number of the solenoid valve 19 for scrum is one, but the idea of this embodiment is that a plurality of solenoid valves 19 for scrum are provided and the power circuits 5 are correspondingly provided. It is also possible to apply the present invention to the case where each of the power circuits is connected to the electromagnetic valves 19 for scrum and the output signals of the switching circuits 19A to 19D are applied in parallel to each other to perform the scrum operation. Further, in the embodiment shown in FIG. 1, a configuration example for driving the scram electromagnetic valve 19 having two exciting coils is shown, but two scram electromagnetic valves having one exciting coil and arranged in series are shown. It is obvious that the concept of the present embodiment can be applied to the case having the above, and it goes without saying that this is also included in the present invention. The scrum solenoid valve is provided in a pipe for operating air that operates an opening / closing valve provided at the outlet of the scrum accumulator of the control rod drive device.

By the way, the exciting coil 16 is excited by the switch unit 5A,
The non-excitation is controlled, and the excitation coil 17 is controlled to be excited or non-excited by the switch section 5B. Assuming that the operation signal for making the exciting coil 16 in the non-excited state is A and the operation signal for making the exciting coil 17 in the non-excited state is B, these operating signals A and B are as follows.

A = ab (c + d) (1) B = cd (a + b) (2) Here, if the scrum signal applied to the scram solenoid valve 19 is Z, the scrum signal Z is expressed by the following equation. .

Z = A + B (3) Substituting the expressions (1) and (2) into the expression (3), the following expression is obtained.

Z = abc + bcd + cda + dab (4) In (4), if any two trip signals of the trip signals a, b, c and d are logic "0", the other trip signals are logic "1". , Then Z = “0”. In other words, it can be seen that a reactor safety protection device with a 2 out of 4 logical configuration that prioritizes logic “0” can be realized. By the way, the number of relays shown in the power circuit 5 is eight,
Since two relays are operated by one trip signal (for example, the relays 8 and 14 are operated by the trip signal a), if a plurality of movable contacts and fixed contacts or relays are used, The number of relays is the same as the power circuit (4). Therefore, it can be seen that a system with a logical configuration of 2 out of 4 can be realized with the same amount of hardware as the conventional one. Also, due to the two-out-of-four logic configuration, one signal processing device or one switching circuit may fail on the safe side (logic "0" side) or the non-safety side (logic "1" side). Accidentally scrum,
Scrum never fails.

Next, in the reactor safety protection device of the present embodiment configured as described above, even if one signal processing device fails or one signal processing device is disconnected for maintenance, the remaining three signal processing devices are used. It is described that 2 out-of-3 logic can be constructed.

This can be achieved by constructing one signal processing system with a signal processing device, a switching circuit and an abnormality diagnosing device as shown in FIG. That is, for example, when the abnormality diagnosing device 22A inputting the status signal of the signal processing device 1 judges an abnormality of the signal processing device 1 based on the input signal, the abnormality diagnosing device 22A is switched to the switching circuit 19A. Disconnect the movable contact 20D of the changeover switch 20 from the fixed contact 20A
Connect to 20B. The power supply 21 is a DC power supply and outputs a signal of logic "1". Thus, by outputting the signal of logic "1" by the switching operation of the switching circuit connected to the signal processing device in the abnormal state, the two out-of-three logic can be configured by the other three normal signal processing devices. In the changeover switch 20 of the changeover circuit, the movable contact 20D in which the signal processing device to which this changeover circuit is connected is normal is in contact with the fixed contact 20A. The switching circuit connects the movable contact 20D to the fixed contact 20B when disconnecting an abnormal signal processing device that transmits the trip signal output from the corresponding signal processing device to the power circuit 5, and outputs a signal of logic "1". Is forcibly transmitted to the power circuit 5. The changeover switch 20 may be controlled by an operator's operation (not shown), or may be performed by an instruction from the abnormality diagnosing device as described above. The abnormality diagnosis devices 22A to 22D can be realized by various means (for example, Japanese Patent Laid-Open No. 59-51393).

As an example, a case where the signal processing device 1 is disconnected will be described. When the signal processing device 1 is in an abnormal state, the diagnostic device 22A
Outputs a command signal to switch the connection of the movable contact 20D of the changeover switch 20 of the changeover circuit 19A from the fixed contact 20A to the fixed contact 20B. At the moment when the connection of the movable contact 20D is switched from the fixed contact 20A to the fixed contact 20B, the changeover switch 20 causes chattering, and the output signal from the fixed terminal 20C is logical "0".
It changes and becomes "1". However, since the power circuit 5 and the exciting coils 16 and 17 have a two-out-of-four logical configuration, chattering does not accidentally scram the reactor. The voltage value of the power supply 21 in which the movable contact 20C is connected to the fixed contact 20B is output. This voltage value is a value that becomes "1" as a logic signal. That is, the signal a output from the switching circuit 19A becomes the logic "1". Substituting the value of the signal a into the equation (4), the scrum signal becomes the following equation.

Z = bc + cd + db (5) As is apparent from the equation (5), when the signal processing device 1 is disconnected, the output signal of the switching circuit 19A of the signal processing system 25A is forced to be logical "1". As a result, the 2 out-of-3 logic can be formed by the output signals from the remaining signal processing devices 2 to 4. As a result, when one signal processing device is disconnected by the switching circuit, even if one of the remaining three normal signal processing devices fails, the reactor is erroneously scrammed when the reactor plant is normal, It is possible to avoid the situation where scrum cannot be performed when scrum is required in the event of an abnormal reactor plant. Further, in the above case, the failure of the remaining three signal processing devices has been described, but the same applies to the case where the switching circuit connected to these signal processing devices fails. The same applies when a relay connected to these switching circuits fails. In other words, even if one signal processing device is disconnected, it is possible to satisfy the prevention of erroneous scrum and the single failure criterion (the scrum function is maintained regardless of any failure of one of the other devices). .

Although the case where the signal processing device 1 is disconnected has been described in the above example, the same applies to the case where the other signal processing devices 2, 3, 4 are disconnected. When disconnecting the signal processing device 2, if the switching circuit 19B is controlled so that b = 1, the scrum signal Z becomes as follows from the equation (4).

Z = ac + cd + da (6) Next, when disconnecting the signal processing device 3, if the switching circuit 19C is controlled so that c = 1, the scrum signal Z becomes as follows from equation (4). .

Z = ab + bd + da (7) Further, when disconnecting the signal processing device 4, if the switching circuit 19D is controlled so that d = 1, the scrum signal Z becomes as follows from the equation (4).

Z = ab + bc + ca (8) That is, in any case, when disconnecting one signal processing device, the output signal of the signal processing system is forcibly set to the logic "1" by the switching circuit, so that 2 The out-of-three configuration can be realized, and the reliability of the reactor safety protection device can be further enhanced.

According to this embodiment, the following effects can be obtained. That is, the independently provided exciting coil 16 for operating the electromagnetic valve for scrum, which is the device to be controlled.
(First operating means), exciting coil 17 (second operating means), and a power circuit 5 including eight switches which are opening / closing devices for operating these exciting coils, and two out-of-four.
Since the logic circuit can be configured, the configuration of the switchgear is significantly simplified, and this simplification improves the reliability of the reactor safety protection device. Further, in a nuclear power plant, the solenoid valve having two exciting coils or the solenoid valve having one exciting coil is left as it is, and two out-of-four units are used.
A logical system can be configured, and one of the four signal processing devices fails, or the system operates erroneously even if one signal processing device is disconnected for maintenance. Since a 2-out-of-3 logical configuration can be constructed without doing or not, it is possible to realize a reactor safety protection device with further improved reliability.

The power circuit 5 of the present embodiment is composed of a switch part (first switchgear) 5A and a switch part (second switchgear) 5B which are provided independently of each other. The switch part 5A and the switch part There is no signal exchange with 5B (switch section 5A
There is no common mode between the switch and the switch unit 5B), which improves the reliability of the switchgear and thus the reliability of the reactor safety protection device. In addition, the signal processing systems 25a, 25B, 25C and 25D arranged in parallel, the relay 8 and the relay 9
And a switch section 5A formed by connecting relays 10 and 11 arranged in parallel in series, and a switch section formed by connecting relays 12, relay 13 and relays 14 and 15 arranged in parallel in series
It is composed of a switchgear having 5B and exciting coils 16 and 17 individually connected to the output terminals of any of the switch parts 5A and 5B, and is output from two of four signal processing systems. Each trip signal is individually relayed 8 and 9
Opening either of the above, the trip signals output from the remaining two signal processing systems are individually relayed to relays 12 and 13
One of the opening operations is performed, and each trip signal output from the former two signal processing systems is individually relayed.
And 15 are opened, and each trip signal output from the latter two signal processing systems is configured to individually open the relays 10 and 11, so the structure of the reactor safety protection device is It is the simplest, and there is no common mode between the switch section 5A and the switch section 5B, and the reliability is the highest. That is, the switch part connected to one exciting coil is composed of four relays.

Since each signal processing system has a switching circuit, it is easy to disconnect the signal processing device in an abnormal state or the signal processing device that performs maintenance from the reactor safety protection device, and the reactor safety by those signal processing devices It is possible to prevent adverse effects on the protective device.

Since it has an abnormality diagnostic device, it is possible to constantly monitor the presence or absence of an abnormality in the signal processing device.

3 and 4 show another embodiment of the present invention, and particularly show the structure near the power circuit. In the reactor safety protection devices of these embodiments, the connection state of each relay and each switching circuit is different from that of the above-mentioned embodiment, and other configurations including parts not shown are the same as those of the first embodiment. This is the same as the illustrated embodiment. In any case, the power circuit 5 and the exciting coils 16 and 17 realize a 2-out-of-4 logical configuration.

First, the embodiment shown in FIG. 3 will be described. The connection state between each relay of the switch parts 5A and 5B and each switching circuit in this embodiment will be described below. That is, the fixed terminals 2 of the switching circuit 19C for the relays 9 and 15 to input the trip signal c.
0C, relays 10 and 12 trip signal b
Is connected to the fixed terminal 20C of the switching circuit 19B for inputting. Therefore, the relay 8 of the switch unit 5A operates with the trip signal a, the relay 9 operates with the trip signal c, the relay 10 operates with the trip signal b, and the relay 11 operates with the trip signal d. On the other hand, the relay 12 of the switch unit 5B receives the trip signal b,
The relay 13 is operated by the trip signal d, the relay 14 is operated by the trip signal a, and the relay 15 is operated by the trip signal c. The excitation coil 16 is controlled to be excited or not excited by the switch section 5A, and the excitation coil 17 is excited by the switch section 5B.
De-excitation is controlled. As a result, the scrum signal Z applied to the solenoid valve 19 for scrum is given by the following equation.

Z = ac (b + d) + bd (a + c) (9) = abc + bcd + cda + dab (10) As is apparent from the equation (10), the scrum signal Z of the present embodiment is the same as the two out-of-four signals in the equation (4). It depends on the logical configuration. Therefore, it can be easily understood that this embodiment also has the same functions and effects as the embodiment of FIG.

Next, the embodiment shown in FIG. 4 will be described. The connection state between each relay of the switch parts 5A and 5B and the switching circuit in this embodiment will be described below. That is, the relays 8 and 14 are connected to the fixed terminal 20C of the switching circuit 19B to input the trip signal b, and the relays 10 and 12 are connected to the fixed terminal 20C of the switching circuit 19A to input the trip signal a. Has been done. Therefore, the relay 8 of the switch unit 5A is operated by the trip signal b, the relay 9 is operated by the trip signal c, the relay 10 is operated by the trip signal a, and the relay 11 is operated by the trip signal d. On the other hand, the relay 12 of the switch unit 5B is operated by the trip signal a, the relay 13 is operated by the trip signal d, the relay 14 is operated by the trip signal b, and the relay 15 is operated by the trip signal c. Therefore, the excitation and non-excitation of the excitation coil 16 are controlled by the switch unit 5A. Further, the excitation / non-excitation of the excitation coil 17 is controlled by the switch section 5B. As a result, the scrum signal Z applied to the solenoid valve 19 for scrum is given by the following equation.

Z = bc (a + d) + ad (b + c) (11) = abc + bcd + cda + dab (12) As is apparent from the equation (12), the scrum signal Z of this embodiment is the same as the two out-of-four equations (4). It has a logical configuration. It can be easily understood that this embodiment also has the same functions and effects as the embodiment of FIG.

FIG. 5 shows another example of incorporating the outputs of the sensors A _{1 to} A ₄ , ..., N _{1 to} N ₄ into the signal processing systems 25A to 25D.

In FIG. 5, the signal processing devices 1 to 4 are designated as the signal processing device 1.
Replaced with A, 2A, 3A and 4A, sensors A ₁ ~ A ₄ , ..., N ₁ ~ N ₄
The respective outputs of 1 are input to all of the signal processing devices 1A, 2A, 3A and 4A. The configuration of the power circuit for inputting the outputs of the switching circuits 19A, 19B, 19C and 19D is the same as that of the power circuit 5 shown in FIG.

The signal processing device 1A includes a digital trip module DTM- connected to the sensors A _{1 to} A ₄ , ..., N _{1 to} N ₄ , respectively.
A1 to DTM-A2, ..., DTM-N1 to DTM-N4. The digital trip modules DTM-A1 to DTM-A4 are sensors A _{1 to} A ₄ that measure the same kind of state quantities, and the digital trip modules DTM-N1 to DTM-N4 are the same kind of state quantities. Connect to the sensors N _{1 to} N ₄ to be measured. One group is made for every four digital trip modules (for example, DTM-A1 to DTM-A2) that input the same state quantity. There are as many groups (n) as there are different types of state quantities. Two out-of-four logic circuits are provided for each group, and the output terminals of the four digital trip modules belonging to one group are connected to one two.
Connect to out-of-four logic. That is, the digital trip modules DTM-A1 to DTM-A4 are connected to the 2 out of 4 logic circuit 29A, ..., The digital trip modules DTM-N1 to DTM-N4 are connected to the 2 out of 4 logic circuit 29N, respectively. It 2 out of 4 logic circuits 29A, ..., 2
As 9N, the number of 2 out-of-4 logic circuits in the signal processing device is n. n 2 out of 4 logic circuits 29
, 29N are connected to one out-of-n logic circuit 30.
The other signal processing devices 2A, 3A and 4A also have the same configuration as the signal processing device 1A. Each one out-of-n logic circuit 30 of the signal processing devices 1A, 2A, 3A and 4A has a corresponding switching circuit 19A,
19B, 19C and 19D, respectively. Each switching circuit 19A, 19B, 19C and 19D in FIG. 5 is connected to each relay of the power circuit as in the embodiment of FIG. Further, each switching circuit and each relay of the power circuit may be connected as in the embodiment of FIGS. 3 and 4. Although the abnormality diagnosing device is not shown in FIG. 5, the signal processing system is composed of the signal processing device, the switching circuit and the abnormality diagnosing device as in FIG.

Each digital trip module of the signal processing device inputs the state quantity signal output by the corresponding sensor and outputs a trip signal when the state quantity signal exceeds a specified value. Each two out-of-four logic circuit of the signal processor outputs a trip signal when at least two digital trip modules of each group output four trip signals. One out-of-n logic circuit is at least one 2 out-of-four logic circuit 26A-26N.
When the trip signal is output from the out-of-four logic circuit, the trip signal a (or trip signal b, c or d) is output. These trip signals a, b, c and d
In the same manner as in the embodiment shown in FIG. 1, the relays of the power circuit are opened to bring the exciting coils 16 and 17 into a non-excited state. As a result, the electromagnet 18 operates, the electromagnetic valve 19 for scrum opens, and the nuclear reactor scrams.

In this way, as shown in FIG. 5, the signal processing devices 1A to 4A
Since 2 out-of-4 logic circuits are used for the signal processing device, high reliability of the signal processing device can be achieved. As a result, the reliability of the reactor safety protection device is further improved.

Another example of the signal processing device will be described with reference to FIGS. 6 and 7.

The signal processing device 35 of the example shown in FIG. 9 is configured by a microprocessor. As shown in FIG. 6, the signal processing device 35 includes a data acquisition circuit 35A, a bus 35B, a CPU 35C, and a RAM 35.
It is composed of a D, ROM 35E and a data output circuit 35F. The data acquisition circuit 35 connected to the n types of sensors is a bus 35B.
Connected to. The bus 35B is connected to the CPU 35C, RAM 35D, ROM 35E and the data output circuit 35F, respectively. ROM35E
Stores the processing procedure shown in FIG. CPU35C is
The arithmetic processing is performed based on the processing procedure stored in the ROM 35E. The RAM 35E stores the data input from the data capture circuit 35A and the data obtained by the CPU 35C. This signal processor 35 is used in place of each of the signal processors 1 to 4 in FIG.

The processing contents for outputting the trip signal based on the processing procedure shown in FIG. 7 will be described by taking the case where the signal processing device 35 is replaced with the signal processing device 1 as an example. The data signals measured by the sensors A ₁ , ..., N ₁ are transferred to R via the data acquisition circuit 35A.
Incorporated into AM35D. The CPU 35C reads the processing procedure shown in FIG. 7 from the ROM 35E. In step 48 of the processing procedure, CPU3
5C reads each measurement data stored in RAM35D. Each read measurement data is compared with a specified value (scrum set value) (step 49). Next, it is determined whether or not there is measurement data that exceeds the specified value (step 50). If there is no measurement data that exceeds the specified value, CPU35C sets a = 1.
Is output (step 51). If there is measurement data that exceeds the specified value, the CPU35C outputs a = 0 (step 5).
2). The obtained value of the signal a is temporarily stored in the RAM 35D and then output from the data output circuit 35F to the switching circuit 19A. Steps 48-50 and 51 or steps 48-50 and 52
The process of is repeated for each input measurement data. When the signal processing device 35 is used for the signal processing devices 2, 3 and 4, respectively, the output signals a of steps 51 and 52 of FIG.
The output signals b, c and d, respectively.

Another example of the processing procedure is shown in FIG. The processing procedure of FIG. 8 is replaced by step 54 instead of step 50 of the processing procedure of FIG.
And step 53 is newly provided. This processing procedure is applied to the case where the measurement data of the sensors A _{1 to} A ₄ , ..., N _{1 to} N ₄ , that is, the measured state quantity signals of all different types are input to the signal processing device 35 four by four. Good to use.
The signal processing device 35 using this processing procedure corresponds to the signal processing device 1A (or 2A to 4A) of the embodiment shown in FIG. Parts different from the processing procedure of FIG. 7 will be described in detail.
It is determined whether at least two measurement data out of the four measurement data of the same type compared in step 49 exceeds the specified value (2 out of 4 logic judgment), and if it exceeds the trip value, a trip signal (logic “0 ") Is output (step 53).
Step 53 is for each of n different types of measurement data,
It is determined whether at least two measurement data of the same type exceed a specified value. Then, the process proceeds to step 54.
It is determined whether or not at least one of the two out-of-four logic determination results of the different types of measurement data in step 53 is logical "0" (step 54). In step 54, if there is no logical "0" judgment result, the processing of step 51 is performed, and the logical "0" judgment result is 1
If so, the process of step 52 is performed.

The reactor safety protection device of each embodiment in which the signal processing device shown in FIGS. 6 to 8 is applied to FIG. 1 can obtain the same effects as the embodiment of FIG. Further, since each signal processing device is composed of a microprocessor, the device becomes compact.

〔The invention's effect〕

According to the present invention, the number of switches of the 2 out of 4 logic circuit can be reduced, so that the reliability can be remarkably increased.
The reliability of reactor protection can be improved.

[Brief description of drawings]

1 is a configuration diagram showing a preferred embodiment of the present invention, FIG. 2 is a detailed diagram of the switching circuit of FIG. 1, and FIGS. 3 and 4 are partial configuration diagrams of another embodiment of the present invention. FIG. 5 is a configuration diagram showing another example of the signal processing device, FIGS. 7 and 8 are configuration diagrams of another embodiment of the power circuit, and FIG. 6 is a configuration diagram of another example of the signal processing device. FIG. 7 is an explanatory view of a processing procedure executed by the signal processing device of FIG. 6, and FIG. 8 is an explanatory view of another processing procedure of the processing procedure of FIG. 1 to 4, 1A to 4A, 35 …… signal processing device, 5, 5C, 5F …… power circuit, 5A, 5B, 5D, 5E …… switch part, 8 to 15 …… relay (or contactor), 16 , 17 …… Excitation coil, 18 ……
Electromagnet, 19 …… Scrum solenoid valve, 19A to 19D …… Change circuit, 20 …… Change switch, 22A to 22D …… Abnormality diagnostic device,
25A-25D …… Signal processing system.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Fumio Murata 3-1-1, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Atomi Noguchi 5-chome, Omika-cho, Hitachi-shi, Ibaraki No. 2 1 Incorporated company Hitachi Ltd. Omika Factory (72) Inventor Shigeru Izumi 1168 Moriyama-cho, Hitachi City, Ibaraki Prefecture Energy Research Institute, Hitachi, Ltd. (72) Tomo Suzuki Suzuki 1168 Moriyama-cho, Hitachi City, Ibaraki Prefecture Energy Research Institute, Nitrate Seisakusho Co., Ltd. (72) Fumiyasu Okido 1168 Moriyama-cho, Hitachi City, Ibaraki Pref. Energy Research Institute, Hitachi, Ltd. (56) References JP 61-118801 (JP, A)

Claims (5)

[Claims] 1. A first, a second, a third and a fourth signal processing system each having a quadruple installed sensor and signal processing means for outputting a trip signal based on an output signal of the sensor. And first and fifth switches operated by a trip signal of the first signal processing system, second and sixth switches operated by a trip signal of the second signal processing system, and the third signal processing system And a fourth and an eighth switch which are opened by a trip signal of the fourth signal processing system, and the third and fourth switches which are operated by a trip signal of The first switch and the second switch are connected in series to the parallel circuit to form a first switching circuit, and the seventh switch and the eighth switch are directly connected to the parallel circuit in which the fifth and sixth switches are connected in parallel. A switchgear that is connected in series to form a second switchgear, first operating means that is connected to the output end of the first switchgear and that operates by the opening operation of the first switchgear, and the second switchgear. Reactor safety comprising second operating means connected to an output end of an opening / closing circuit and operated by an opening operation of the second opening / closing circuit, and a controlled device operated when the first and second operating means are operated. Protective device. 2. The method according to claim 1, wherein
And the second operating means are excitation coils, respectively, and the controlled device is a solenoid valve provided with an electromagnet having the two excitation coils. 3. A quadruple installed sensor, a signal processing means for outputting a trip signal based on an output signal of the sensor, and a switching means for outputting a logic signal for holding a closed state of a switch described later, respectively. Have first, second, third
And a fourth signal processing system, and first and fifth switches which are opened by a trip signal of the first signal processing system,
Second and sixth switches operated by a trip signal of the second signal processing system, third and seventh switches operated by a trip signal of the third signal processing system, trip of the fourth signal processing system A fourth circuit and an eighth switch which are opened by a signal, and the first switch and the second switch are connected in series to a parallel circuit in which the third and fourth switches are connected in parallel to form a first switching circuit. And a switch device for forming a second switch circuit by connecting the seventh switch and the eighth switch in series to a parallel circuit formed by connecting the fifth switch and the sixth switch in parallel, and an output of the first switch circuit. First operating means connected to the end and operated by the opening operation of the first switching circuit, and second operating means connected to the output terminal of the second switching circuit and operated by the opening operation of the second switching circuit. And before First and reactor safety protection device and a control target device to be operated upon actuation of the second operating means. 4. The claim 3 according to claim 3, wherein each of the four signal processing systems has a diagnosing means for diagnosing an abnormality of its own signal processing means, and corresponds to a case where the diagnosing means diagnoses an abnormality. A reactor safety protection device, wherein each switch outputs a logic signal that holds a closed state. 5. The signal processing system according to claim 3, wherein each of the four signal processing systems outputs a logical signal for holding a corresponding closed switch when electrically disconnected from the system. Reactor safety protection device.